Multiple cut-out for telephone systems



(No Model.) 2 Sheets-Sheet 1 A. B. STROWGER 81; A. E. KEITH. MULTIPLECUT-OUT FOR TELEPHONE SYSTEMS.

No. 589,798. 4 Patented Sept. 7, 1897.

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2 Sheets-Sheet 2 A. B. STROWGER 8a A. E. KEITH. MULTIPLE GUT-OUT FORTELEPHONE SYSTEMS.

No. 589,798. Patented Sept. 7, 1897.

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UNITED STATES PATEN ALMOX l3. STROWGER AND ALEXANDER E. KEITH, OFCHICAGO, ILLINOIS.

MULTIPLE CUT-OUT FOR TELEPHONE SYSTEMS.

SPECIFICATION forming part of Letters Patent No. 589,798, datedSeptember 7, 1897.

2 Application filed February 19, 1896- Serial No. 579,846. (No model.)

To all/Z whom it may concern.-

Be it known that we, ALMON 13. Srnowonr. and ALEXANDER E. KEITH,citizens of the United States, residing at Chicago, in the county ofCook and State of Illinois, have invented a new and useful MultipleCut-Out for Telephone and Telegraph Systems, of which the following is aspecification.

Our invention relates to telephone, telegraph, and other similarapparatus, but is herein shown and described as applied to a telephonesystem.

Our object is to provide means whereby two-line-wires instead of servingto connect one telephone set with a central exchange may serve toconnect a plurality of telephone sets therewith, the mechanism andelectrical connections being such that but one operator may connect at atime, all the others being automatically cut out from the normallycommon circuit, as is fully explained hereinafter and'is illustrated inthe accompanying drawings, in which Figure 1 is a diagrammatic view ofthe several parts and electrical connections which in combination formour invention, the same being shown in the normal position to il1ustratethe first course of the currents of electricity which serve to operatethe combined cut-out and switch apparatus. Fig. 2 is a diagrammatic viewsimilar to Fig. 1, but with several of the parts in a changed positionto show the course of the current after part of the combined cut-out andswitch is operated. Fig. 3 is a detached portion of Fig. 2, showing theaction of an automatic cut-out, which is fully described hereinafter.

Similar letters and figures indicate like parts throughout the severalviews.

Grouped at B and O mechanism is shown which accompanies each telephoneset, and consists of signal-keys H, T, and U, telephone a, and the usuallever 5, upon which it is suspended, this lever having a piece ofinsulating material 6 at the under side to contact a metal spring 7,which in turn contacts another metal spring 8, when thetelephonereceiver is hung on the leveigthese springs being attached atthe fixed end to a piece of insulating material. 8".

At 9 is a lever to which is attached the armature of an electromagnet10, the lever being held back against a stop by means of a spring, asshown.

At 11 is a metal spring-arm attached to a pin at one end, and the upperfree end may be vibrated either way, so as to simultane ously contactterminals 12 and 13 on one side or terminals 14 and 15 on the other.

The spring-arm 11 projects beyond the ter-- 'the other end contacts thelever 9 when it is in the normal position shown in Fig. 1, but is out'ofcontact therewith when the lever has been moved to the position shown inFig. 3.

At 19, 20, 21, and 22 are representations of automatic telephoneexchange machines, which have, respectively, interconnecting wires 23,24, 25, and 26 and an interconnecting wire 27, which latter wireterminates at the switch-arm 28 of the manual exchangeboard 29.

The several automatic telephone-exchange machines shown each have ashaft 30, which is operated by means of magnets 31 and 32 to cause theswitch-arm or wiper 33, attached to the shaft, to contact theinterconnecting wires shown or an additional number of such wires, asmay be required, this kind of automatic telephone-exchange shown beingthe subject of Letters Patent of the United States No. 540,168, datedMay 28, 1895.

In both Figs. 1 and 2 at A are shown the signal-keys and telephonecommon to groups B and C, but in group A are not shown the magnets 10and 1'7 nor any of the mechanism operated by them, since group A represents the extreme end of the series of sub stations connected with thesame line and none of the above-named cut-out and switching mechanism isrequired at this terminal station, since the electric current forenergizing magnets 10 and 17 at substation B is controlled at keys II,T, and U at station A and the electric currents for energizing magnets10 and 17 at substation C is controlled at keys II, T, and U at somepreceding substation, such as A or 13, &c., and so on, as is is directlyconnected to the line-wires 34and 35, to which are connected,successively, the three substations A, B, and C.

The operation of this system is as follows: Supposing that a person atsubstation B desires to connect with the telephone-exchange machine 19and with the telephone at some substation which is connected with thiseX- change by wires 36 and 37, the first operation is to remove thetelephone 4 from the lever 5, when the lever will rise by "virtue of thespring connected therewith and assume the position shown in Fig. 2,substation B, when springs 7 and 8 move out of contact, whichdisconnects substation A and any other intermediate stations betweensubstations A and B. If now signal-key H is operated at station E, thecourse of the current is from battery 38 at the central station throughwire 39, thence through wire 39', then through the exchange-switch 22,thence through linewire 35 to wire 36 at substation O, through spring 8,spring 7, wire 37, then wire 38, electromagnet 10, line-wire 35, toterminal 14 of substation B, to spring-arm 11, terminal 15, wire 40,signal-key II, to ground. This current energizes magnet 10 at allsubstations between substation B and the central eX- change, causinglever 9 to be depressed against spring-arm 11, which disconnectsterminals 14 and 15 and connects terminals 12 and 13 and holds theselatter terminals in contact therewith by the falling of the bellcranklever 16, whose hook engages the end of the spring-arm 11, as shown inFig. 3, and after the current is released still holds the spring-arm inthis position, as shown in Fig. 2 at substation C. The foregoingoperations of removing the telephone from lever 5 thus cuts out allsubstations between substation l3 and the central exchange by thedisconnection of terminals 14 and 15 of all of said intermediatestations. It will thus be seen that a person at substation B is inpossession of the line to the exclusion of all others. It will be seenthat after this operation the current divides at the junction of thelines 35 and 36, one portion thereof passing from terminal 14 throughwire '41 to terminal 12, spring-arm 11, terminal 13, wire 38, anduniting with the other current at the junction of wires 37 and 38, theother portion from line 35 passing into wire 36, springs 8 and 7, andwire 37 to wire 38, as before stated.

The lifting of telephone 4 at substation C will not affect substation B,for the whole current will not divide at the junction of wires and 33,but proceed through terminals 14 and 12, as before stated.

The manner in which the several cut-outs and switches are made to assumetheir nor mal positions is as follows: Referring to Fig. 2, Sheet 2,station B, first press key H, when current passes from battery 38through wires 39 and 39, through the telephone-exchange machine 22, toline-wire 35, where the current divides (if springs 7 and 8 under lever5 are in contact) at the junction of wires 35 and 36 of substation 0,one portion thereof passing from terminal 14 through wire 41 to terminal12, spring-arm 11, terminal 13, wire 38, and uniting with the otherportion of the current at the junction of wires 37 and 38', the otherportion from line 35 passing into wire 36. springs 8 and 7, and wire 37to wire 38, as be fore stated, thence in full current through magnet 10,line-wire 35, to terminal 14 of substation B. thence to spring-arm 11,terminal 15, wire 40, and key H to ground.

In the passage of the current as last described it energizes magnet 10of substation O and, depressing lever 9, breaks the contact therewith ofspring 18, as shown in Fig. 3,

and, while holding key H in contact and at the same time depressing keyT, causes current to pass from battery through wire 39 to 39, throughthe exchange-machine 22, thence through line-wire 34 to magnet 17 ofsubstation C, thence by line-wire 34 to wire 42, to key T, toground,whereby magnet 17 at substation 0 is energized, causing the hookof bell-crank lever 16 to disengage from the end of spring-arm 11, whichbreaks contact with terminals 12 and 13, and arm 11 springs into contactwith terminals 14 and 15, which is the normal position. This operationof release last described is usually performed automatically by hangingup the telephone-receiver instead of by manipulating the signalkeysdescribed, and forms a part of the subject of application for Patent ofthe United States for electrical exchanges, Serial No. 556,229, filedJuly 17, 1895.

After spring-arm 11 has been set to the position shown in Fig. 2 atsubstation O or any other station between substation B and the centralexchange 22, if the key T at substation B is manipulated for any purposethe force of the current from battery 38 would pass directly throughmagnet 17 of substation G, if this magnet had no shunt, and cause itto'operate bell-crank lever 16 and disengage the hook thereof from theend of spring-arm 11 and thus bring these parts back to the normalposition, but to prevent this a shuntcircuit is provided for magnet 17by way of wire 42fro1n wire 34 to wire 43, lever 9, spring 18, and wire44 to line-wire 34 at the opposite side of magnet 17 not enough currentpassing through this magnet on account of its much higher resistancethan the shunt-wires, which are very short, to energize the magnet TOOsufficient to attract the armature of bell-crank lever 16 and releasethe spring-arm 11.

We claim as our invention 1. The combination, with a central station, ofaseries of substations, an electrical circuit comm on to all of thestations, a switch, a locking device and two magnets for eachsubstation, one of the magnets beiu g connected with one of the wiresand the other magnet being connected with the other wire, and means formoving the switch in one direction by one of the magnets and causing itto automatically engage with the locking device, and means for releasingthe switch by the other magnet, and means for completing the circuitthrough either of the substations, substantially as set forth.

2. The combination, with a central station, of a seriesof substations,an electrical circuit common to all the stations, a switch, two magnets,a lock, operating mechanism, a shunt around the switch provided with twoterminals and a holder for the telephone-receiver in each substation,said holder being adapted to close the terminals when the receiver is inposition, one of the magnets being connected with one line of thecircuit, and the other magnet being connected with the other line, andmeans for moving the switch into engagement with the look by one of themagnets and for releasing it by the other magnet, substantially as setforth.

The combination with a telephone or other electric circuit extendingbetween a central station and a series of substations on the same line,each substation normally in electrical connection with the centralstation, of mechanism at the substations consisting of an automaticcut-out adapted to be actuated by the removal ofthe telephone and breakconnection between the central station and all substations preceding theone at which the before-mentioned cut-out is operated, each substationexceptthe last or terminal substa tion in the circuit having apparatuscomprising two electromagnets, one magnet in the circuit of each line,one of such magnets adapted to operate a cut-out and break the circuitof the substation in which it is located, while the other magnet servesto release the cutout whereby it may return to the normal position, thecurrents for operatingthese magnets being controlled by means located atsome preceding substation, substantially as hereinbefore described.

In testimony that we claim the foregoing we have hereunto set our hands,this 7th day of September, 1895, in the presence of witnesses.

ALMON B. STROWGER. ALEXANDER E. KEITH.

Witnesses:

J OSEPH HARRIS, OSCAR SNELL.

